Field of Invention
The present invention relates to a detection method, and more particularly to a capacitive sensing detection method.
Description of Related Art
Touch sensing technology capable of providing a natural interface between an electronic system and user has found widespread applications in a variety of fields, for example, in mobile phones, personal digital assistants (PDAs), automatic teller machines (ATMs), game machines, medical devices, liquid crystal display (LCD) devices, computing devices, and the like, where a user may input desired information and/or operate the electronic system through a touch sensing device associated with the electronic system.
There are different types of touch sensing devices available for detection of a touch position. One is a resistive-type touch sensing device that includes two layers of transparent conductive material, such as a transparent conductive oxide, separated by a gap. When touched with sufficient force, one of the conductive layers flexes to make contact with the other conductive layer. The position of the contact point is detectable by a controller that senses the change in resistance at the contact point. In response, the controller performs a function, if any, associated with the contact point.
Another one is a capacitive-type touch sensing device. The capacitive-type touch sensing device can be classified into two types: an analog capacitive sensing device, which uses a contiguous resistive layer, and a mutual-type projected capacitive sensing device, which uses patterned conductive layers (electrodes).
In a projected capacitive touch device, the touch sensor employs a series of patterned electrodes that are driven with a signal from a controller. Similarly, a touch position of the contact point can be derived from currents flowing through one or more corresponding electrodes toward the touch point responsive to the touch with sensing the capacitance induced by a user's finger. A finger touch to the sensor provides a capacitive couple from the conductive layer to the body. The touch position of the contact point is detectable by a controller that measures a change in a capacitively coupled electrical signal at the touch position. Accordingly, the controller performs a function, if any, associated with the touch position.
Typically, a touch panel using the capacitive touch sensing detection has those advantages including waterproof, anti scratch and high rate of transmission. Moreover, it is also very convenient for a user to use his finger to control this kind of touch panel. However, an additional touch panel is needed to detect the touch position. The touch panel and the pixel matrix are stacked together, which increases the thickness of the display. Therefore, a new capacitive sensing detection method that can be directly performed in the pixel matrix is required.